Q.1 Please explain the personalization tab within a role?
Personalization is a way to save information that could be common to users, I meant to a user role… E.g. you can create SAP queries and manage authorizations by user groups. Now this information can be stored in the personalization tab of the role. (I supposed that it is a way for SAP to address his ambiguity of its concept of user group and roles: is “usergroup” a grouping of people sharing the same access or is it the role who is the grouping of people sharing the same access).

Q.2 Is there a table for authorizations where I can quickly see the values entered in a group of fields?
In particular I am looking to find the field values for P_ORGIN across a number of authorization profiles, without having to drill down on each profile and authorization. AGR_1251 will give you some reasonable info.
Q.3 How can I do a mass delete of the roles without deleting the new roles ?
There is a SAP delivered report that you can copy, remove the system type check and run. To do a landscape with delete, enter the roles to be deleted in a transport, run the delete program or manually delete and then release the transport and import them into all clients and systems.
It is called: AGR_DELETE_ALL_ACTIVITY_GROUPS. To used it, you need to tweak/debug & replace the code as it has a check that ensure it is deleting SAP delivered roles only. Once you get past that little bit, it works well.

Q.4 How to insert missing authorization?
su53 is the best transaction with which we can find the missing authorizations.and we can insert those missing authorization through pfcg.
Q.5 What is the difference between role and a profile?
Role and profile go hand in hand. Profile is bought in by a role. Role is used as a template, where you can add T-codes, reports..Profile is one which gives the user authorization. When you create a role, a profile is automatically created.

Q.6 What profile versions?
Profile versions are nothing but when u modifies a profile parameter through a RZ10 and generates a new profile is created with a different version and it is stored in the database.

Q.7 What is the difference between USOBX_C and USOBT_C?
The table USOBX_C defines which authorization checks are to be performed within a transaction and which not (despite authority-check command programmed ). This table also determines which authorization checks are maintained in the Profile Generator.
The table USOBT_C defines for each transaction and for each authorization object which default values an authorization created from the authorization object should have in the Profile Generator.

Q.10 What is the difference between the table buffer and the user buffer?
The table buffers are in the shared memory. Buffering the tables increases performance when accessing the data records contained in the table. Table buffers and table entries are ignored during startup. A user buffer is a buffer from which the data of a user master record is loaded when the user logs on. The user buffer has different setting options with regard to the ‘auth/new_buffering’ parameter.